Abstract: An object of the invention is to receive a weak signal with high sensitivity and reduce distortion and signal suppression when a strong interference signal exists. When a high-frequency signal received by an antenna is to be amplified by an antenna amplifier and when an interference wave of high field strength exists, a switch circuit is switched by an output switchover circuit from the output of an amplifier to a through-circuit. The through-circuit guides the high-frequency signal, directly to the output side without passing through the amplifier. When the switching operation of the switch circuit is performed based on low-frequency components which are highly correlated with distortion components due to intermodulation, the switching operation can be performed more adequately. Noises can be reduced by performing a smoothing process on the switching operation, and the use of an inverting amplifier can prevent occurrence of oscillation.

Abstract: A rod antenna with a good reception sensitivity using a conductive body of a vehicle or a heater element of a defogger as a reflector, that is, a rod antenna to be mounted at a conductive outside surface of a vehicle or at an outside surface of a rear window of a vehicle where heater elements of a defogger are arranged in parallel, provided with a rod-shaped antenna element provided with a predetermined length and a holding member comprised of a base member for holding the antenna element and an antenna support member, the holding member holding the antenna element so that it is separated a predetermined distance from the outside surface so that the outside surface becomes a reflector for the antenna element.

Abstract: An audio broadcast receiving apparatus and an audio broadcast receiving method implemented by the audio broadcast receiving apparatus are disclosed. A tuner simultaneously receives a radio wave in a specific frequency band of the analog audio broadcast and a radio wave of the digital audio broadcast transmitted in parallel with the analog audio broadcast in the specific frequency band. A demodulator retrieves the intended audio information by demodulating the signal received by the tuner. An analog receiving signal bandpass filter selectively passes the receiving signal corresponding to the analog audio broadcast radio wave. An analog receiving signal amplifier outputs an output signal representing an amplified receiving signal that has passed the analog receiving signal bandpass filter to the demodulator, and the gain of the amplifier is controlled in accordance with the level of the same output signal.

Abstract: The invention aims to reduce the amount of circuitry in a receiver for receiving broadcast radio waves transmitted using an IBOC system that allows simultaneous transmissions of an analog broadcast and a digital broadcast with the same content. The amount of circuitry is reduced by making provisions to reproduce only a monaural signal from an analog demodulator. To reduce the unnaturalness that may occur when switching from the digital broadcast to the analog broadcast, a blend processing section mixes the two signals in a smoothly varying ratio during the switching.

Abstract: An audio broadcast receiving apparatus and an audio broadcast receiving method implemented by the audio broadcast receiving apparatus are disclosed. A tuner simultaneously receives a radio wave in a specific frequency band of the analog audio broadcast and a radio wave of the digital audio broadcast transmitted in parallel with the analog audio broadcast in the specific frequency band. A demodulator retrieves the intended audio information by demodulating the signal received by the tuner. An analog receiving signal bandpass filter selectively passes the receiving signal corresponding to the analog audio broadcast radio wave. An analog receiving signal amplifier outputs an output signal representing an amplified receiving signal that has passed the analog receiving signal bandpass filter to the demodulator, and the gain of the amplifier is controlled in accordance with the level of the same output signal.

Abstract: When configuring a film antenna for receiving a circular polarized wave, at least one loop antenna is formed on a transparent plastic film and, at the same time, a non-powered element constituted by a wire-shaped conductor independent from the antenna conductor configuring the loop is arranged near this loop antenna. The non-powered element arranged on the side of the loop antenna is configured by a first part and a second part. The first part is made close to the loop antenna in a substantially parallel state. When a monopole antenna is used in place of the loop antenna, by combining this with a wire-shaped conductor orthogonal to this, it becomes possible to receive a circular polarized wave by a configuration providing a power transfer part between the two. It is also possible to configure a composite antenna by mounting another antenna on the transparent plastic film. This antenna can be used as an antenna of a navigation system.

Abstract: An object of the invention is to receive a weak signal with high sensitivity and reduce distortion and signal suppression when a strong interference signal exists. When a high-frequency signal received by an antenna is to be amplified by an antenna amplifier and when an interference wave of high field strength exists, a switch circuit is switched by an output switchover circuit from the output of an amplifier to a through-circuit. The through-circuit guides the high-frequency signal, directly to the output side without passing through the amplifier. When the switching operation of the switch circuit is performed based on low-frequency components which are highly correlated with distortion components due to intermodulation, the switching operation can be performed more adequately. Noises can be reduced by performing a smoothing process on the switching operation, and the use of an inverting amplifier can prevent occurrence of oscillation.

Abstract: The present invention is intended to detect pulse noise entering an AM receiver in order to improve the freedom in construction and prevent erroneous operation. It provides a pulse noise detecting circuit in an AM receiver having an envelope detecting portion (108) that performs envelope detection on an intermediate frequency signal and outputs a gate signal for removing a pulse noise signal mixed in an output signal of the envelope detecting portion including a high pass filter (31) that blocks the envelope detection signal from the envelope detecting portion (108) and extracts the pulse noise signal, an amplifier (32) that amplifies the extracted pulse noise, a level detecting portion (33) that detects the level of the amplified pulse noise signal and outputs the gate signal when the level is a predetermined value, and a second band filter (34) that extracts the envelope detection signal and adjusts the smoothed amplification to make the level of the pulse noise signal constant.

Abstract: A branching filter, which is operatively connected between an antenna and a communication device which utilizes different frequency bands, suppresses a mutual interference between signals transmitted to and from the communication device. An antenna circuit, which is operatively connected between the antenna, or a branching filter, and the communication device, converts an impedance with respect to a signal in a frequency band having a lower frequency, and reduces loss resulting from a capacitive antenna impedance.

Abstract: An antenna element including a loading coil is telescopically extendable and retractable from within a housing tube. A characteristic impedance of a transmission line from a lower end part of the antenna element to a cable is equal to one of a cable. A part of the loading coil is reinforced. A branching filter, which is operatively connected between the antenna and a communication device using a different frequency band, suppresses a mutual interference between signals for the communication device. An antenna circuit, which is operatively connected between the antenna or a branching filter and the communication device, converts an impedance of a lower part in a frequency band, and reduces a loss due to a capacitive antenna impedance.

Abstract: Disclosed is a mobile radio-receiver system built-into an FM radio-receiver set installed in a vehicle, wherein a reproduction characteristic of a reception signal, such as a sound signal, having noise superimposed thereon is improved. The mobile radio-receiver system includes a space diversity unit which receives two reception signals and selects one reception signal on which noise is smaller than on the other reception signal, and a signal prediction unit which ignores the selected signal for a predetermined time in which large noise remains in the selected signal, and predicts a reception signal for the ignored selected signal for the predetermined time, so that a quality of a reproduction sound from the FM radio-receiver set is greatly improved.

Abstract: A noise reduction apparatus in which an input signal is supplied to a first signal path (2) including a variable low-pass filter (2) and a second signal path (1), a control circuit (4) control is such that a cut-off frequency of the variable low-pass filter (2) is varied in accordance with a frequency of the input signal S(1), and an output signal is obtained from the first signal path when noise is generated and from the second signal path when noise is not generated.

Abstract: A hollow cathode ion source for in a vacuum chamber wherein it comprises a cylindrical cathode through one end of which a gaseous medium of at least a discharge maintaining gas or said discharge maintaining gas and a metal vapor is or are introduced, and an anode provided on the other end of said cylindrical cathode and having at least one ion extraction opening, said gaseous medium being ionized by a discharge means between said cylindrical cathode and said anode to produce ions which are extracted through said ion extraction opening in the axial direction of said cylindrical cathode.The cylindrical cathode in the ion source has a large diameter at least about half and preferably about equal to its axial length and may be directly cooled.

Abstract: An electric cell comprising a positive electrode, a negative electrode, and an electrolyte containing a lithium salt is provided wherein the negative electrode has a two-layer structure of a lithium-aluminum alloy layer and an aluminum layer. The cell is fabricated by placing a positive electrode, a negative electrode, and an electrolyte in a cell container comprising positive and negative electrode casings, and forming a seal between the positive and negative electrode casings. The negative electrode is electrochemically formed in situ in the cell container from a lithium-clad aluminum substrate.

Abstract: Ion source including an electric discharge chamber body divided by a partition, having an anode electrode therein, into a main discharge chamber and a subsidiary discharge chamber. The subsidiary discharge chamber has a filament mounted therein aligned with at least one small opening through the partition wall and the anode electrode. An inert gas opening is provided into the subsidiary discharge chamber. An electric discharge gas opening and an ion outlet opening are provided to the main discharge chamber. Magnets are provided outside of the chamber body for creating a magnetic field extending nearly along an axis of the at least one small opening in the anode electrode.

Abstract: A high frequency amplifier circuit includes a series resonance circuit resonating at a desired frequency, first transistor to the gate of which are applied signals and to the source of which is connected the series resonance circuit, a second transistor to the base of which is applied the output signal from the first transistor, and third and fourth transistors having their emitters connected to the second transistor. The collector of the third transistor is connected to the source of the first transistor. A parallel resonance circuit resonates at the desired frequency. The collector of the fourth transistor is connected to the source of the first transistor via the parallel resonance circuit. An AGC circuit applies AGC voltage to the bases of the third and fourth transistors for the purpose of varying the collector current ratio of both the transistors. Negative feedback is accomplished in the circuit, and output power is obtained from the parallel resonance circuit.

Abstract: An intermediate frequency detection circuit of a superheterodyne type radio receiver is disclosure which includes a logic circuit inputted with a signal indicating the level of an intermediate frequency output and a signal indicating the level of a high frequency output of the receiver. This logic circuit generates a indication of the reception of a broadcasting wave when the intermediate frequency output is high and the high frequency output is low. This intermediate frequency detection circuit avoids the erroneous detection due to spurious signals and likewise renders the pulse width of the detection signal approximately constant thus making this circuit suitable for use with automatic channel selection.

Abstract: An antenna input circuit for an electronic tuning type AM receiver for automobiles, which is connected to a capacitive antenna represented by an equivalent circuit composed of an antenna capacitance connected in series with an antenna electromotive force and a cable capacitance connected in parallel with them. A tuning transformer and a variable capacitance diode are connected in series with the capacitive antenna, and an additional capacitance is connected to the tuning transformer so that the current flowing in the additional capacitance also flows in one part of the tuning transformer, thereby providing an improved S/N ratio in the medium-frequency receiving band. Another capacitance is connected to the output terminal of the antenna input circuit, to reduce its output impedance. A capacitance for image interference ratio improving use is connected to the additional capacitance and the output impedance reducing capacitance.

Abstract: A selective amplifier whose gain characteristic is rendered approximately uniform over the entire frequency band to be amplified with no degradation in the S/N ratio. The amplifier consists of a band-pass filter and an amplifying element, in which a resistor for eliminating the ripples in the transmission characteristic of the filter is constituted with a feed back resistor for the amplifying element, the coil for the parallel resonance circuit in the filter is constituted as an auto-transformer and the capacitor in the serial resonance circuit of said filter is formed with the capacitance of a capacitive antenna respectively to thereby improve the S/N ratio. The amplifier is suitable to be used at the top of the high frequency stages in a radio receiver.

Abstract: A radio receiver comprises an antenna circuit represented by an equivalent circuit consisting of an antenna electromotive force, an antenna capacitance in series with said electromotive force and a cable capacitance in parallel with them, a negative capacitance circuit connected to the antenna circuit for at least partially cancelling the antenna capacitance and the cable capacitance and a tuning circuit for receiving the output of the antenna circuit. The negative capacitance circuit, composed of a capacitor, transistors and the like, improves the S/N ratio.